Robinson opened the scoring in the sixth minute before notching his third goal in two games with a superb volley 16 minutes later.

The game was made safe when Nmecha scored twice after half-time following assists from on-form Robinson.

It was a deserved reward in a match which saw North End - who kept their play-off hopes mathematically alive for another three days at least - dominate as Town slipped to a 15th away defeat of the season.

Sean Maguire had a powerful shot saved by Bartosz Bialkowski on four minutes as the hosts started strongly at Deepdale.

And the early pressure paid off when Robinson rifled home from the edge of the box to put Preston ahead two minutes later.

Aristote Nsiala blocked a Nmecha effort for a corner before Ben Davies headed against the post from the resulting set-piece.

Flynn Downes failed to find target from distance for the visitors and their task got much harder when Robinson doubled his tally with a fine volley into the top corner on 22 minutes.

The lively Nmecha then cleared Luke Chambers' looping header off the line after he got on the end of Alan Judge's corner.

Judge shot just over shortly after, when his own corner fell back into his path and the Tractor Boys survived penalty shouts as Nmecha went down under a Chambers challenge.

Robinson fired straight at Bialkowski after linking up well with Nmecha, while Teddy Bishop had an effort saved by Declan Rudd on 38 minutes, before he flashed an effort narrowly wide on the stroke of half-time.

Bialkowski's brilliant double save firstly kept out Robinson, then Nmecha, in first-half stoppage time as Ipswich made the safety of the changing rooms with just a two-goal deficit.

Maguire headed just wide from Joseph Rafferty's cross shortly after the restart and any hopes of an unlikely comeback were effectively ended when Nmecha slotted home a rebound after Robinson's first effort was saved on 56 minutes.

Kayden Jackson then hit the crossbar after he got on the end of Bialkowski's long clearance following a defensive mix-up between Rudd and Jordan Storey before Storey and Davies produced superb blocks to stop Will Keane getting a consolation goal.

And it was game over when Nmecha found the back of the net after more great play involving Robinson on 75 minutes as the Lilywhites now lie seven points outside the top six with three games remaining.

The managers

Alex Neil: "We had good quality at times when we needed it and Callum Robinson was involved in all four goals, so I think that shows his importance to us," said Neil.

"He's a good player, he is one of our key players. What he did here, not every player can do. He had the quality to damage them.

"After the last week it was important we came out and put on a good performance and put things right."

Paul Lambert: "We never turned up," Lambert said. "We didn't play well at all and I thought we looked a yard short.